Cellulosic composition of matter containing dibenzyl succinate



Patented Oct. 4, :1932

UNITED sraras HENRY B. SMITH, OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK COM- PANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK CELLULOSIC COMPOSITION OF MATTER CONTAINING IDIBIE'NZY L SUCCINATE No Drawing.

This invention relates to compositions of matter in which cellulose derivatives, such as cellulose acetate, cellulose nitrate or cellu lose ether, are combined or mixed with other substances, such as a compatible plasticizer, and a common solvent for both, with or without other useful addition agents, so that the resulting product will have properties such as will make the composition highly advantageous for use in the plastic and analogous arts, such, for instance, as the manufacture of wrapping sheets, photographicfilm, artificial silk, varnishes or lacquers, and the like.

One object of this invention is to produce a composition of matter which may be made into permanently transparent, strong and flexible sheets or films of desired thinness which are substantially waterproof, are unaffected by ordinary photographic fluids and possess the desired properties of a support for sensitive photographic coatings. Another object of my invention is to produce a composition which is capable of easy and convenient manipulation in the plastic and analogous arts, such as in the manufacture of sheets, films, artificial silk filaments, varnishes, lacquers and the like, and to produce a composition which will not injure, or be injured by, the substances or surfaces with which it is associated during manufacture. Other objects will become apparent to those skilled in the art to which this invention pertains.

While cellulose acetates, nitrates and ethers have been known for decades it has also been known that to utilize them in the various plastic arts it is necessary to mix therewith such plasticizing or conditioning agents as camphor, castor oil, triphenyl phosphate, monochlornaphthalene or the like.

Certain of these and other addition agents are also added for the purpose of reducing the inflammability of the product. Plastic inducing agents, such as the higher alcohols and their esters, are sometimes also added. Similarly addition compounds of various kinds have been employed to increase flexibility, transparency, toughness and other properties which will enhance the value of the resulting product. Addition products Application filed August 23, 1930. Serial No. 477,478. 7

for the same or similar purposes are also added to cellulose acetates, nitrates and matter of considerable importance to the art.

I have discovered that valuable properties may be induced in and/or contributed to com positions containing cellulose derivatives, such as cellulose acetate, by adding thereto the plasticizing compound dibenzyl succinate together with a solvent, such as acetone, which will dissolve both the cellulose derivative and plasticizer. This plasticizer has the general formula:

It is compatible with cellulose derivatives and particularly compatible with cellulose acetate in the percentages hereinafter given. It is not an expensive compound and not particularly difiicult to produce, or obtain upon the open market. The particularly useful properties which it induces in or contributes to a cellulosic composition containing it are hereinafter enumerated.

In order that those skilled in this art may better understand my invention I would state, by way of illustration, that for the manufacture of photographic film or other sheets my new composition of matter may be compounded as follows: 100 parts of acetone soluble'cellulose acetate i. e. cellulose acetate containing from 38% to 42% acetyl radical, approximately, is dissolved with stirring at atmospheric temperature in 300 to 500 parts, preferably 400 parts, by weight, of acetone. To this solution may be added from 10 to 50 parts by weight, of dibenzyl'succinate, it being found preferable to employ approximate- 1y 30 to 40 parts thereof. Within the limits stated, the amount of plasticizer may be decreased or increased, depending upon whether it is desired to decrease or increase, respectively, the properties which this plasticizer contributes to the finished product. The amount of solvent employed may also be de creased or increased, depending upon whether it is desired to have a more or less freely flowing composition, respectively.

A composition of matter prepared as above described may be deposited upon any suitable film forming surface to form a film or sheet, as is well known to those skilled in the art. A film so produced has permanently brilliant transparency and low infiammability, burning no more readily than ordinary newsprint. Such film is exceedingly tough and flexible, as shown by the fact that it will withstand many folds upon a modified Schopper foldtester (commonly used for such purposes) without breaking and that even after being subjected for a considerable number of days to air maintained at a temperature of C. the film still maintains flexibility (in contrast to almost complete lack of flexibility where no plasticizer is used) demonstrating that the film will withstand ordinary usage satisfactorily for many years. The sum total of the above advantageous properties of a product produced from my new composition is considerably in excess of that of products produced with what have previously been regarded as the better plasticizers.

Other similar solvents (instead of acetone) which are compatible with the cellulose acetate and my new plasticizer may also occur to those skilled in this art. In like manner this plasticizer may be compounded with other single organic esters of cellulose, such as cellulose propionate, butyrate and the like, or with mixed organic and/or inorganic esters, such as cellulose aceto-stearate, acetomalate, or cellulose nitro-acetate, or with'the cellulose ethers, a suitable solvent which will dissolve both the cellulosic derivative and the plasticizer being employed. 7

V Inasmuch as my above described composition of matter is quite useful'in the producplasticizer may also be employed with advantage in connection with a number of the known lacquer and varnish formulae with which it may be found to be compatible. In

such cases the plasticizer is usually first put into solution with the cellulose derivative solution and if non-solvents are added for the purpose of cheapening the composition they are added only to such an extent as will not precipitate the derivative from solution, Also the plasticizer is usually employed in larger amounts, such as from 50 to 60 parts,

in compounding lacquers. Other uses within the scope of my invention will also suggest themselves to those skilled in the art.

VVhatI claim as my invention, and desire to be secured by Letters Patent of the United States, is:

1. A composition of matter comprising a cellulose derivative and dibenzyl succinate.

2. A composition of matter comprising cellulose acetate and dibenzyl succinate.

3. A composition of matter comprising cellulose acetate, 'dibenzyl succinate, and a solvent common to both. I

4. A composition of matter comprising cellulose acetate, acetone and dibenzyl succinate.

5. A composition of matter comprising 100 parts cellulose acetate and from about 10 to 60 parts, by weight, of dibenzyl succinate.

6. A composition of matter comprising 100 parts of cellulose acetate and approximately 30 to 50 parts, by weight, of dibenzyl succinate.

Signed at Rochester, New York, this 15th day of August, 1930.

HENRY B. SMITH.

tion of films and sheets it will beapparent that my new plasticizer may also be employed with advantage in the other branches of the plastic art. For instance, my, above described composition of matter may be em ployed in the manufacture of artificial silk by the dry spinning method. With the proper coagulating bath it may also be employed for wet spinning. It may be desired to employ a composition of diflerent viscosity 0r evaporation characteristics but this is a mere matter of changing the solvent proportion or adding evaporation retardents such as triacetin or other high or intermediate boiling constituents, as hasfbeen well known in the art for more thana decade. My novel 

